JP2015216517A - Photoelectric converter and signal transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photoelectric converter that can suppress radiation noise and a signal transmission device using the same.SOLUTION: A photoelectric converter has a power supply line 31 to which a power supply voltage is applied, an electrical signal line 32 for transmitting an electrical signal, an optical signal line 33 for transmitting an optical signal, an optical element 42 for performing signal conversion between the electrical signal and the optical signal, a signal processor 41 for performing at least one of output of an electrical signal to the optical element 42 and signal processing of an electrical signal output from the optical element 42, a ferrite bead 51 connected to a low-potential side line 312, and a three-terminal capacitor 6 connected between a high-potential side line 311 and the low-potential side line 312. The GND electrode 62 of the three-terminal capacitor 6 is connected to be nearer to the signal processor 41 side than the ferrite bead 51.

Description

  The present invention generally relates to a photoelectric conversion device and a signal transmission device, and more particularly to a photoelectric conversion device that converts a signal between an electrical signal and an optical signal, and a signal transmission device using the same.

  Conventionally, an optical element that converts an electrical signal into an optical signal to emit light, or receives light to convert an optical signal into an electrical signal, and signal processing to transmit an electrical signal to or receive an electrical signal from the optical element There is a photoelectric conversion device provided with a section (see, for example, Patent Document 1). In the photoelectric conversion device described in Patent Document 1, a light emitting side photoelectric conversion unit and a light receiving side photoelectric conversion unit each including an optical element and a signal processing unit are connected by an external waveguide, and light is transmitted through the external waveguide. Transmit the signal.

  In addition, the photoelectric conversion device described in Patent Document 1 includes a light emission side photoelectric conversion unit and a light reception side photoelectric conversion unit for supplying power between the light emission side photoelectric conversion unit and the light reception side photoelectric conversion unit. Are connected with a flexible cable.

JP 2009-260227 A

  However, in the photoelectric conversion device described in Patent Document 1, noise from the light emission side photoelectric conversion unit and the light reception side photoelectric conversion unit propagates to the flexible cable used for power supply, and radiation noise from the flexible cable increases. There was a fear.

  This invention is made | formed in view of the said reason, The objective is to provide the photoelectric conversion apparatus which can suppress radiation noise, and a signal transmission apparatus using the same.

  The photoelectric conversion device of the present invention has a high-potential side line and a low-potential side line, a power supply voltage is applied between the high-potential side line and the low-potential side line, and the counterpart side is connected via a power cable. A power line connected to the device, an electrical signal line for transmitting an electrical signal, an optical signal line for transmitting an optical signal and connected to the counterpart device via an optical cable, and optically connected to the optical signal line An optical element that is connected and converts between the electrical signal and the optical signal, the power supply voltage is applied, the electrical signal output to the optical element, and the electrical signal signal output from the optical element A signal processing unit that performs at least one of processing, an inductance element connected between the signal processing unit and the power cable in the low potential side line, and the power cable side of the signal processing unit. A capacitance element connected between the high-potential side line and the low-potential side line, wherein the capacitance element is connected to the low-potential side line at a position closer to the signal processing unit than the inductance element. It is characterized by being.

  In this photoelectric conversion apparatus, the low potential side line includes a plurality of inductance elements connected in series between the signal processing unit and the power cable, and the plurality of inductance elements have impedance characteristics with respect to frequency. Preferably they are different from each other.

  In this photoelectric conversion device, it is preferable that the inductance element is composed of a ferrite bead.

  In this photoelectric conversion device, it is preferable that a high-potential side inductance element connected between the signal processing unit and the power supply cable is provided in the high-potential side line.

  In the photoelectric conversion device, the high potential side line includes a plurality of high potential side inductance elements connected in series between the signal processing unit and the power supply cable, and the plurality of high potential side inductance elements include: The impedance characteristics with respect to frequency are preferably different from each other.

  In this photoelectric conversion device, the high potential side inductance element is preferably composed of ferrite beads.

  In this photoelectric conversion apparatus, it is preferable that the capacitance element is constituted by a three-terminal capacitor.

  The signal transmission device of the present invention includes a pair of the photoelectric conversion devices described above, and further, the power cable connecting the power lines of the pair of photoelectric conversion devices, and the light of the pair of photoelectric conversion devices. And an optical cable for connecting signal lines to each other.

  As described above, the present invention has an effect that noise transmitted from the power supply line to the power supply cable can be suppressed by connecting the capacitance element and the inductance element to the power supply line, and radiation noise can be suppressed.

It is a block block diagram of the photoelectric conversion apparatus and signal transmission apparatus of embodiment. It is an equivalent circuit diagram of the three-terminal capacitor in the embodiment. It is a block block diagram of the 1st modification of the photoelectric conversion apparatus and signal transmission apparatus in embodiment. It is a block block diagram of the 2nd modification of the photoelectric conversion apparatus and signal transmission apparatus in embodiment. It is a graph which shows the noise evaluation result of the signal transmission apparatus in an embodiment. It is a graph which shows the noise evaluation result of the signal transmission apparatus in an embodiment. It is a graph which shows the noise evaluation result of the conventional signal transmission apparatus. It is a graph which shows the noise evaluation result of the conventional signal transmission apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment)
FIG. 1 shows a block configuration diagram of the photoelectric conversion apparatus 1 and the signal transmission apparatus 10 of the present embodiment. The present embodiment is a photoelectric conversion apparatus 1 that performs signal conversion between an electric signal and an optical signal, and a signal transmission apparatus 10 that uses the photoelectric conversion apparatus 1. The signal transmission device 10 includes a pair of photoelectric conversion devices 1 and a connection cable 2 (a power cable 21 and an optical cable 22) for connecting the pair of photoelectric conversion devices 1 to each other. In the meantime, communication using the optical signal and power supply are performed via the connection cable 2. When distinguishing each of the pair of photoelectric conversion devices 1, the photoelectric conversion device 1 that converts an electric signal into an optical signal and transmits the signal is referred to as a transmission device 1T, and receives the optical signal and converts the signal into an electric signal. The photoelectric conversion device 1 that performs this operation is referred to as a receiving device 1R. And the photoelectric conversion apparatus 1 of this embodiment suppresses radiation noise by providing the ferrite bead 51 and the three-terminal capacitor 6 as noise countermeasure components.

  Below, the detailed structure of the photoelectric conversion apparatus 1 of this embodiment and the signal transmission apparatus 10 is demonstrated.

  The photoelectric conversion apparatus 1 (transmission apparatus 1T, reception apparatus 1R) of this embodiment includes a power line 31, an electric signal line 32, an optical signal line 33, a signal processing unit 41, an optical element 42, and a ferrite bead 51 (inductance element). And a three-terminal capacitor 6 (capacitance element). The transmission device 1T and the reception device 1R have the same configuration, and the transmission device 1T and the reception device 1R are configured so that the input and output of the electrical signal and the optical signal are symmetrical. The transmission device 1T converts the electrical signal input from the first external device 11 into an optical signal and transmits the optical signal to the reception device 1R that is the counterpart device. The receiving device 1R receives an optical signal transmitted from the transmitting device 1T that is the counterpart device, converts the optical signal into an electric signal, and transmits the electric signal to the second external device 12. When distinguishing between the configuration of the transmission device 1T and the configuration of the reception device 1R, the configuration of the transmission device 1T is suffixed with “T”, and the configuration of the reception device 1R is suffixed with “R”. "Will be described.

  First, the configuration of the transmission device 1T will be described.

  The power supply line 31T is made of, for example, a metal conductor formed on a printed board (not shown), and includes a high potential side line 311T and a low potential side line 312T. One end of each of the high potential side line 311T and the low potential side line 312T is electrically connected to the first external device 11 via the connector 34T. A power supply voltage (for example, direct current 5.0V or 3.3V) is applied between the high potential side line 311T and the low potential side line 312T by the first external device 11. An external power supply (not shown) different from the first external device 11 is electrically connected to the power supply line 31T via the connector 34T, and the high potential side line 311T and the low potential side line 312T are connected by this external power supply. The power supply voltage may be applied between them.

  The low potential side line 312T is electrically connected to GND (ground). The other ends of the high potential side line 311T and the low potential side line 312T are electrically connected to the connection cable 2. The connection cable 2 of the present embodiment is configured by a photoelectric composite cable integrally including a power cable 21 (high potential side cable 211, low potential side cable 212) for transmitting power and an optical cable 22 for transmitting an optical signal. Yes. The other end of the high potential side line 311T is electrically connected to the high potential side cable 211 of the power cable 21 and the other end of the low potential side line 312T is electrically connected to the low potential side cable 212 of the power cable 21. Has been.

  The electric signal line 32T is made of, for example, a metal conductor formed on a printed circuit board, one end is electrically connected to the first external device 11 via the connector 34T, and the other end is a signal processing unit 41T described later. Is electrically connected. The electric signal line 32T transmits an electric signal transmitted from the first external device 11 to the signal processing unit 41T.

  The signal processing unit 41T is used as a driver for driving the optical element 42T, and uses a power supply voltage applied from the first external device 11 via the power supply line 31T as a power supply. The signal processing unit 41T drives the optical element 42T by performing signal processing such as signal amplification and filtering on the electric signal input via the electric signal line 32T and outputting the signal to the optical element 42T.

  The optical element 42T is configured by a VCSEL (Vertical Cavity Surface Emitting Laser) or an LED (Light Emitting Diode) that is a semiconductor laser. The optical element 42T is used as a light emitting element that emits light when supplied with a current. The light emitting element 42T receives the electrical signal and flashes to emit light, thereby converting the electrical signal into an optical signal.

  The optical signal line 33T is configured by a transmission path including a core (not shown) that transmits light, and is provided on, for example, a silicon substrate (not shown). One end of the optical signal line 33T is optically coupled to the optical element 42T, and the other end is optically coupled to the optical cable 22 of the connection cable 2. The optical signal line 33T transmits the optical signal transmitted from the optical element 42T to the optical cable 22. The optical signal line 33T and the optical cable 22 may be integrally formed.

  In addition, the transmission device 1T of the present embodiment includes ferrite beads 51T and a three-terminal capacitor 6T as noise countermeasure components that suppress noise propagating from the power supply line 31T to the power supply cable 21.

  The ferrite bead 51T is composed of a chip type ferrite bead inductor. The ferrite bead 51T is electrically connected to be inserted between the signal processing unit 41T and the power cable 21 (low potential side cable 212) in the low potential side line 312T. The ferrite bead 51T is not limited to the configuration of the chip-type ferrite bead inductor, and may be a configuration including a ferrite core and a lead wire penetrating the ferrite core. Further, instead of the ferrite bead 51T, another inductance element having an inductance component may be used.

  The three-terminal capacitor 6T is composed of a chip-type three-terminal capacitor, and includes a pair of through electrodes 61T (through electrodes) and a GND electrode 62T. The pair of through electrodes 61T of the three-terminal capacitor 6T are electrically connected so as to be inserted between the signal processing unit 41T and the power cable 21 (low potential side cable 212) in the high potential side line 311T. The GND electrode 62T of the three-terminal capacitor 6T is electrically connected to the low potential side line 312T on the signal processing unit 41T side than the ferrite bead 51T.

  Here, the three-terminal capacitor 6T is configured such that the pair of through electrodes 61T are electrically connected inside the element, and a dielectric is interposed between the pair of through electrodes 61T and the GND electrode 62T, and an equivalent circuit is shown in FIG. As shown. The through electrode 61T and the GND electrode 62T have a minute inductance (so-called residual inductance), but the residual inductance of the through electrode 61T is inserted into the high potential side line 311T. Therefore, the electrical component generated by the three-terminal capacitor 6T between the high potential side line 311T and the low potential side line 312T becomes the residual impedance and capacitance of the GND electrode 62T, and the residual impedance of the through electrode 61T is Not included.

  The three-terminal capacitor 6T of the present embodiment includes one GND electrode 62T, but may be configured to include a pair of GND electrodes 62. In the present embodiment, only one three-terminal capacitor 6T is provided, but a configuration including a plurality of three-terminal capacitors 6T may be used. Note that the three-terminal capacitor 6T is not limited to the configuration of the chip-type three-terminal capacitor, and may be a lead-type three-terminal capacitor in which a lead wire is connected to an electrode. Further, instead of the three-terminal capacitor 6T, another capacitance element having a capacitance component may be connected between the high potential side line 311T and the low potential side line 312T.

  Although not shown in FIG. 1, a two-terminal capacitor in which a dielectric is interposed between a pair of electrodes is electrically connected between the high potential side line 311T and the low potential side line 312T (GND). It may be connected.

  Further, the transmission device 1T is configured to cover the power supply line 31T, the electric signal line 32T, the optical signal line 33T, the signal processing unit 41T, the optical element 42T, the ferrite bead 51T, the three-terminal capacitor 6T, and the connector 34T. 7T is provided. The casing 7T is made of, for example, a metal material, and suppresses radiation noise from the photoelectric conversion device 1. Note that the housing 7T may be configured to be electrically connected to the GND or may be configured to be electrically insulated from the GND.

  Next, the configuration of the receiving device 1R will be described.

  The power supply line 31R has the same configuration as the power supply line 31T of the transmission apparatus 1T, includes a high potential side line 311R and a low potential side line 312R, and is electrically connected to the power supply line 31T of the transmission apparatus 1T via the power supply cable 21. It is connected to the. Therefore, a power supply voltage is applied from the first external device 11 between the high potential side line 311R and the low potential side line 312R of the reception device 1R via the transmission device 1T and the power cable 21. Furthermore, one end of each of the high potential side line 311R and the low potential side line 312R is electrically connected to the second external device 12 via the connector 34R. The second external device 12 can use the power supply voltage output from the first external device 11 as a power source. In the present embodiment, the first external device 11 is configured to output the power supply voltage. However, the second external device 12 may be configured to output the power supply voltage.

  The optical signal line 33R has the same configuration as the optical signal line 33T of the transmission device 1T, and one end is optically coupled to the optical cable 22 of the connection cable 2 and the other end is optically coupled to the optical element 42R. . The optical signal line 33R transmits the optical signal transmitted from the transmission device 1T to the optical element 42R.

  The optical element 42R is composed of, for example, a photodiode, and is used as a light receiving element that generates a current by receiving light. The optical element 42R receives the optical signal that is blinking light and intermittently generates a current or a voltage, thereby converting the optical signal into an electrical signal.

  The signal processing unit 41R performs signal processing such as signal amplification and filtering on the electrical signal output from the optical element 42R, and outputs the signal to the electrical signal line 32R.

  The electrical signal line 32R has the same configuration as the electrical signal line 32T of the transmission device 1T, and one end is connected to the second external device 12 via the connector 34R. The electrical signal output from the signal processing unit 41R is transmitted to the second external device 12 via the electrical signal line 32R and the connector 34R.

  The ferrite bead 51R and the three-terminal capacitor 6R have the same configuration as that of the ferrite bead 51T and the three-terminal capacitor 6T of the transmitter 1T, and are connected to the same locations.

  The casing 7R has the same configuration as the casing 7T of the transmission device 1T, and includes a power supply line 31R, an electric signal line 32R, an optical signal line 33R, an optical element 42R, a signal processing unit 41R, a ferrite bead 51R, and a three-terminal capacitor 6R. The connector 34R is configured to be covered.

  As described above, the transmission device 1T and the reception device 1R have the same configuration, and the transmission device 1T and the reception device 1R are configured so that the input / output of the electrical signal, the optical signal, and the power supply voltage is symmetrical. Has been.

  Further, a shield member 213 is provided in the high potential side cable 211 constituting the connection cable 2 so as to cover the periphery of the high potential side cable 211. The shield member 213 is composed of a braided shield in which a metal wire is knitted, and is electrically connected to the housing 7. The shield member 213 may be configured to be electrically connected to GND, or may be configured not to be electrically connected to GND. The shield member 213 may be a member that suppresses radiation noise, and is not limited to a braided shield, and may be formed of, for example, a metal film, a metal tube, or an electromagnetic wave absorbing material that absorbs electromagnetic waves.

  As described above, the photoelectric conversion device 1 (the transmission device 1T and the reception device 1R) and the signal transmission device 10 according to the present embodiment are ferrite beads as a noise countermeasure component that suppresses noise propagating from the power line 31 to the power cable 21. 51, a three-terminal capacitor 6 is provided.

  In the low potential side line 312, an inductance element (ferrite bead 51) is connected between the signal processing unit 41 and the power cable 21 (low potential side cable 212). By this inductance element, noise propagating from the low potential side line 312 to the power cable 21 (low potential side cable 212) is suppressed. Furthermore, in this embodiment, the noise suppression effect can be improved by using the ferrite bead 51 provided with a ferrite as an inductance element. Moreover, since the ferrite bead 51 of this embodiment is comprised by the chip-type ferrite bead inductor, size reduction of the photoelectric conversion apparatus 1 can be achieved.

  A capacitance element (three-terminal capacitor 6) is connected between the high potential side line 311 and the low potential side line 312 on the power cable 21 side of the signal processing unit 41. By this capacitance element, noise on the high potential side line 311 can be released to the low potential side line 312 (GND) via the dielectric, and propagated from the high potential side line 311 to the power cable 21 (high potential side cable 211). Noise is suppressed. Further, the capacitance element is connected so that the connection portion with the low potential side line 312 is closer to the signal processing unit 41 than the ferrite bead 51. Therefore, it is possible to suppress the noise that has escaped from the high potential side line 311 via the dielectric from propagating to the low potential side cable 212. Further, in the present embodiment, a three-terminal capacitor 6 is used as a capacitance element. When the three-terminal capacitor 6 is connected between the high potential side line 311 and the low potential side line 312, the residual impedance generated between the high potential side line 311 and the low potential side line 312 is connected to the two terminal capacitor. Smaller than the case. Therefore, by using the three-terminal capacitor 6, noise on the high potential side line 311 can be efficiently released to the low potential side line 312 (GND), so that the noise suppression effect can be improved. Further, since the three-terminal capacitor 6 of the present embodiment is constituted by a chip-type three-terminal capacitor, the photoelectric conversion device 1 can be reduced in size.

  Therefore, even when noise propagates from the electric signal line 32, the signal processing unit 41, the optical element 42, etc. to the power supply line 31, it propagates from the power supply line 31 to the power supply cable 21 by the ferrite bead 51 and the three-terminal capacitor 6. Noise is suppressed. Thereby, the radiation noise from the power cable 21 can be suppressed.

  Furthermore, since the shield member 213 is provided in the high potential side cable 211, radiation noise from the high potential side cable 211 can be further suppressed. Moreover, since the photoelectric conversion apparatus 1 is provided with the housing | casing 7 formed with a metal material, the radiation noise from the photoelectric conversion apparatus 1 can also be suppressed.

  The connection cable 2 may further include a shield member that is provided so as to cover the periphery of the low-potential side cable 212 and suppresses radiation noise. Moreover, the structure provided so that the shield member may integrally cover the circumference | surroundings of the high potential side cable 211 and the low potential side cable 212 may be sufficient. Further, the shield member may be configured to integrally cover the periphery of the high potential side cable 211, the low potential side cable 212, and the optical cable 22.

  In the present embodiment, the connection cable 2 that connects the transmission device 1T and the reception device 1R is configured by a photoelectric composite cable that integrally includes a power cable 21 and an optical cable 22, but the power cable 21 and the optical cable 22 are included. And may be configured separately.

  Moreover, the photoelectric conversion apparatus 1 may include a plurality of signal processing units 41 and optical elements 42, and may be configured to allow multi-channel communication and bidirectional communication.

  Next, a first modification of the present embodiment will be described with reference to FIG. In this modification, as shown in FIG. 3, the ferrite bead 52 (high potential side inductance element) is also connected to the high potential side line 311. The ferrite bead 52 has the same configuration as the ferrite bead 51 and is electrically connected so as to be inserted between the signal processing unit 41 and the power cable 21 (high potential side cable 211) in the high potential side line 311. Is done. The inductance element (ferrite bead 52) suppresses noise propagating from the high potential side line 311 to the power cable 21 (high potential cable 211), so that radiation noise from the power cable 21 can be further suppressed. . Furthermore, in this embodiment, the noise suppression effect can be improved by using the ferrite bead 52 provided with a ferrite as an inductance element.

  In this modification, as shown in FIG. 3, the ferrite bead 52 is connected to the signal processing unit 41 side from the three-terminal capacitor 6, but is connected to the power cable 21 side from the three-terminal capacitor 6. Even with this configuration, a noise suppression effect can be obtained.

  Next, as a second modification of the present embodiment, as shown in FIG. 4, even if a plurality of ferrite beads 51 and 52 are connected to the high potential side line 311 and the low potential side line 312 respectively. Good. The photoelectric conversion apparatus 1 of this modification includes two ferrite beads 52 connected in series between the signal processing unit 41 and the power cable 21 in the high potential side line 311. Further, the photoelectric conversion device includes two ferrite beads 51 connected in series between the signal processing unit 41 and the power cable 21 in the low potential side line 312. The two ferrite beads 51 are referred to as ferrite beads 511 and 512, and the two ferrite beads 52 are referred to as ferrite beads 521 and 522. Here, the ferrite bead 511 and the ferrite bead 512 are configured to have different impedance characteristics with respect to the frequency, and the ferrite bead 511 has a lower frequency at which the impedance value peaks than the ferrite bead 512. Further, the ferrite bead 521 and the ferrite bead 522 are configured to have different impedance characteristics with respect to the frequency, and the ferrite bead 521 has a lower frequency at which the impedance value peaks than the ferrite bead 522. That is, the ferrite beads 511 and 521 mainly suppress low frequency noise, and the ferrite beads 512 and 522 mainly suppress high frequency noise.

  As described above, in the present modification, the ferrite beads 521 and 522 having different impedance characteristics are connected to the high potential side line 311, and the ferrite beads 511 and 512 having different impedance characteristics are connected to the low potential side line 312. The photoelectric conversion apparatus 1 of the present modification includes a plurality of ferrite beads 51 and 52 having different impedance characteristics with respect to frequency, thereby suppressing noise in various frequency bands from propagating from the power line 31 to the power cable 21. be able to.

  In this modification, two ferrite beads 51 and 52 are provided, but three or more ferrite beads 51 and 52 may be provided. Moreover, the structure provided with two or more either of the ferrite beads 51 and 52 may be sufficient.

Next, the noise suppression effect by the ferrite beads 511, 512, 521, 522 and the three-terminal capacitor 6 will be described using the noise evaluation results shown in FIGS. Note that the noise evaluation method is based on the technical standard “V3 / 2013.04” of the VCCI Association (Council for Voluntary Control of Radio Wave Information Processing Equipment). The transmission signal used for noise evaluation has a frequency set to 5 Gbps and a signal pattern set to PRBS2 ⁷ -1 (Pseudo Random Bit Sequence). 5 and 6 show the noise evaluation results of the signal transmission device 10 of this embodiment provided with the ferrite beads 511, 512, 521, and 522 and the three-terminal capacitor 6, and FIG. 6 is the electric field intensity of vertically polarized waves [a. u. ] Is shown. 7 and 8 show the noise evaluation results of a conventional signal transmission apparatus that does not include the ferrite beads 511, 512, 521, and 522 and the three-terminal capacitor 6T. FIG. 7 shows horizontal polarization, and FIG. 8 shows vertical polarization. Wave field strength [a. u. ] Is shown. Also, the solid line L1 in FIGS. 5 and 7 indicates the determination criterion for horizontal polarization, and the solid line L2 in FIGS. 6 and 8 indicates the determination criterion for vertical polarization.

  As shown in FIGS. 7 and 8, in the conventional signal transmission device that does not include the ferrite beads 511, 512, 521, and 522 and the three-terminal capacitor 6, noise that propagates from the power line 31 to the power cable 21 is not suppressed. Therefore, radiation noise from the power cable 21 is large, and there is a frequency band that exceeds the determination criteria L1 and L2. On the other hand, as shown in FIGS. 5 and 6, the signal transmission device 10 of the present embodiment is configured to reduce noise from the power line 31 to the power cable 21 by the ferrite beads 511, 512, 521, 522 and the three-terminal capacitor 6. Propagation is suppressed. Therefore, radiation noise from the power cable 21 is small and falls below the determination criteria L1 and L2 in all frequency bands.

  As described above, the photoelectric conversion device 1 and the signal transmission device 10 according to the present embodiment include the ferrite beads 511, 512, 521, 522, and the three-terminal capacitor 6 as noise countermeasure components. Thereby, it is possible to suppress the propagation of noise in various frequency bands from the power supply line 31 to the power supply cable 21. Therefore, radiation noise from the power cable 21 can be further suppressed.

  The above-described embodiment is an example of the present invention. For this reason, the present invention is not limited to the above-described embodiment, and various modifications can be made according to design and the like as long as the technical idea according to the present invention is not deviated from this embodiment. Of course, it can be changed.

DESCRIPTION OF SYMBOLS 1 Photoelectric conversion apparatus 10 Signal transmission apparatus 21 Power supply cable 22 Optical cable 31 Power supply line 311 High electric potential side line 312 Low electric potential side line 32 Electric signal line 33 Optical signal line 41 Signal processing part 42 Optical element 51 Ferrite bead (inductance element)
52 Ferrite beads (high-potential side inductance element)
6 Three-terminal capacitor (capacitance element)

Claims (8)

A power supply line having a high potential side line and a low potential side line, a power supply voltage is applied between the high potential side line and the low potential side line, and connected to a counterpart device via a power cable;
An electrical signal line for transmitting electrical signals;
An optical signal line that transmits an optical signal and is connected to the counterpart device via an optical cable;
An optical element that is optically connected to the optical signal line and converts between the electrical signal and the optical signal;
A signal processing unit that is applied with the power supply voltage and that performs at least one of output of the electrical signal to the optical element and signal processing of the electrical signal output from the optical element;
In the low potential side line, an inductance element connected between the signal processing unit and the power cable;
A capacitance element connected between the high potential side line and the low potential side line on the power cable side of the signal processing unit;
In the photoelectric conversion device, the capacitance element is connected to the low potential side line at a position closer to the signal processing unit than the inductance element. In the low potential side line, comprising a plurality of the inductance elements connected in series between the signal processing unit and the power cable,
The photoelectric conversion apparatus according to claim 1, wherein the plurality of inductance elements have different impedance characteristics with respect to frequency. The photoelectric conversion apparatus according to claim 1, wherein the inductance element is formed of a ferrite bead. 4. The optoelectric device according to claim 1, further comprising a high-potential side inductance element connected between the signal processing unit and the power cable in the high-potential side line. 5. Conversion device. In the high potential side line, comprising a plurality of high potential side inductance elements connected in series between the signal processing unit and the power cable,
The photoelectric conversion apparatus according to claim 4, wherein the plurality of high-potential side inductance elements have different impedance characteristics with respect to frequency. The photoelectric conversion apparatus according to claim 4 or 5, wherein the high-potential side inductance element is composed of a ferrite bead. The photoelectric conversion device according to any one of claims 1 to 6, wherein the capacitance element includes a three-terminal capacitor. A pair of photoelectric conversion devices according to any one of claims 1 to 7,
Further, the power cable connecting the power lines of the pair of photoelectric conversion devices,
The signal transmission device comprising: the optical cable connecting the optical signal lines of the pair of photoelectric conversion devices.

Images